This invention relates to a process for welding together aluminum and copper, and especially to the butt and corner welding of aluminum and copper conductors using a pulse laser.
To weld aluminum to copper without obtaining a brittle joint has been an inherent metallurgical problem; this brittleness results from the formation of intermetallic compounds which are inherently brittle themselves. One area where a copper to aluminum weld is employed is in small ac motors. A cold welded copper to aluminum transition piece, in series between the conductors, is presently being used to join aluminum wound stator coils to copper power leads. One method of making the transition joint is by flash welding. The surfaces of the mating materials are metallurgically bonded by a high forging pressure produced by force and the speed of approaching surfaces during current arcing. Elimination of the transition piece and direct joining of the coil leads to the power leads would represent a savings in labor and materials.